They (collect) ..had collected. more than 100 pounds of moon rocks and done science experiments on the lunar surface before they (come) ..came. back to the Earth.
Fill each blank with a suitable word to complete the following passage. Spaceexploration is the investigation of the universe beyond the Earth’s atmosphere, by (1) ________ of manned or unmanned spacecraft. Despite the technological advancements achieved in the past, space exploration was only (2) _______ until the 20th century. The first successful orbital launch was made by the Soviet Union in 1957 which was called “Sputnik”. When the topic “SPACE EXPLORATION” is put (3)_______ the table, a question has often been asked: “Why should we spend money on NASA while there are so (4) _______ problems here on Earth?” However, this might be partially wrong since exploring the unknown may help us progress. The advantages of space exploration include the materials (5) ________ can be obtained from outer space. For instance, asteroids have iron and nickel which could be utilized to satisfy the (6) ________ for metal. Therefore, numerous commercial companies have invested in developing technology for asteroid mining. Several comets and asteroids (7) ________ solid water in them. This water can be used for astronauts and scientists in space stations. The water can also be broken down to hydrogen which can be used as (8) ______ for the rockets. Scientists also believe that dinosaurs disappeared because they couldn’t go to (9) ________ planet. Sooner or later a killer comet will again cross Earth’s path, threatening all life. Fortunately, (10) _________we have knowledge about comets and space science, we will be able to survive.
In 1543, Nicolaus Copernicus (publish) ... "On the Revolutions of the Heavenly Spheres" claiming that the earth and the planets (orbit) ... the sun.
"Did you see the new 3D film at Megastars Theater?" - "Yes. It was better than good. It's was ..."
A. over the moon B. once in blue moon C. the sky's the limit D. out of this world
It is merely of the universe an optical illusion of the moon ... appears considerably larger than it does.
A. who B. whose C. whom D. which
On Feb. 15, 1971, Shepard and Mitchell (land) ... on the moon.
..., I go to the cinema, only when there's a film I really, really want to see.
A. Over the moon B. Once in a blue moon C. The sky's the limit D. Out of this world
To walk on the moon, the astronauts had to carry a suitcase ... contained oxygen.
A. which B. it C. having D. where
Europe's biggest ISS project is the Columbus science laboratory ... astronauts can carry out scientific experiments in weightless conditions.
A. which B. where C. when D. there
On the ISS ... have to attach themselves so they don't float around.
A. astronauts B. astronautics C. astronautically D. astronautical
